zerotier: Migrate from clanModule to clanServices

This migrates zerotier from clanModules to clanServices.
This is a graceful migration and does not yet disables any of the
clanModule functionality.

clanServices/flake-module.nix

@@ -5,5 +5,6 @@
     ./hello-world/flake-module.nix
     ./wifi/flake-module.nix
     ./borgbackup/flake-module.nix
+    ./zerotier/flake-module.nix
   ];
 }

clanServices/zerotier/README.md

@@ -0,0 +1,44 @@
+---
+description = "Configures [Zerotier VPN](https://zerotier.com) secure and efficient networking within a Clan."
+features = [ "inventory" ]
+categories = [ "Network", "System" ]
+
+[constraints]
+roles.controller.min = 1
+roles.controller.max = 1
+roles.moon.max = 7
+---
+
+## Overview
+
+This guide explains how to set up and manage a [ZeroTier VPN](https://zerotier.com) for a clan network. Each VPN requires a single controller and can support multiple peers and optional moons for better connectivity.
+
+## Roles
+
+### 1. Controller
+
+The [Controller](https://docs.zerotier.com/controller/) manages network membership and is responsible for admitting new peers.
+When a new node is added to the clan, the controller must be updated to ensure it has the latest member list.
+
+- **Key Points:**
+  - Must be online to admit new machines to the VPN.
+  - Existing nodes can continue to communicate even when the controller is offline.
+
+### 2. Moons
+
+[Moons](https://docs.zerotier.com/roots) act as relay nodes,
+providing direct connectivity to peers via their public IP addresses.
+They enable devices that are not publicly reachable to join the VPN by routing through these nodes.
+
+- **Configuration Notes:**
+  - Each moon must define its public IP address.
+  - Ensures connectivity for devices behind NAT or restrictive firewalls.
+
+### 3. Peers
+
+Peers are standard nodes in the VPN.
+They connect to other peers, moons, and the controller as needed.
+
+- **Purpose:**
+  - General role for all machines that are neither controllers nor moons.
+  - Ideal for most clan members' devices.

clanServices/zerotier/default.nix

@@ -0,0 +1,151 @@
+{ ... }:
+{
+  _class = "clan.service";
+  manifest.name = "clan-core/zerotier";
+  manifest.description = "Configuration of the secure and efficient Zerotier VPN";
+  manifest.categories = [ "Utility" ];
+  manifest.readme = builtins.readFile ./README.md;
+
+  roles.peer = {
+    perInstance =
+      { instanceName, roles, ... }:
+      {
+        nixosModule =
+          {
+            config,
+            lib,
+            pkgs,
+            ...
+          }:
+          {
+            imports = [
+              (import ./shared.nix {
+                inherit
+                  instanceName
+                  roles
+                  config
+                  lib
+                  pkgs
+                  ;
+              })
+            ];
+          };
+      };
+  };
+
+  roles.moon = {
+    interface =
+      { lib, ... }:
+      {
+        options.zerotier.moon.stableEndpoints = lib.mkOption {
+          type = lib.types.listOf lib.types.str;
+          description = ''
+            Make this machine a moon.
+            Other machines can join this moon by adding this moon in their config.
+            It will be reachable under the given stable endpoints.
+          '';
+          example = ''
+            [ 1.2.3.4" "10.0.0.3/9993" "2001:abcd:abcd::3/9993" ]
+          '';
+        };
+
+      };
+    perInstance =
+      { instanceName, roles, ... }:
+      {
+        nixosModule =
+          {
+            config,
+            lib,
+            pkgs,
+            settings,
+            ...
+          }:
+          {
+            config.clan.core.networking.zerotier.moon.stableEndpoints = settings.zerotier.moon.stableEndpoints;
+
+            imports = [
+              (import ./shared.nix {
+                inherit
+                  instanceName
+                  roles
+                  config
+                  lib
+                  pkgs
+                  ;
+              })
+            ];
+          };
+      };
+  };
+
+  roles.controller = {
+    perInstance =
+      {
+        instanceName,
+        roles,
+        ...
+      }:
+      {
+        nixosModule =
+          {
+            config,
+            lib,
+            pkgs,
+            ...
+          }:
+          let
+            uniqueStrings = list: builtins.attrNames (builtins.groupBy lib.id list);
+          in
+          {
+            imports = [
+              (import ./shared.nix {
+                inherit
+                  instanceName
+                  roles
+                  config
+                  lib
+                  pkgs
+                  ;
+              })
+            ];
+            config = {
+              systemd.services.zerotier-inventory-autoaccept =
+                let
+                  machines = uniqueStrings (
+                    (lib.attrNames roles.moon.machines)
+                    ++ (lib.attrNames roles.controller.machines)
+                    ++ (lib.attrNames roles.peer.machines)
+                  );
+                  networkIps = builtins.foldl' (
+                    ips: name:
+                    if
+                      builtins.pathExists "${config.clan.core.settings.directory}/vars/per-machine/${name}/zerotier/zerotier-ip/value"
+                    then
+                      ips
+                      ++ [
+                        (builtins.readFile "${config.clan.core.settings.directory}/vars/per-machine/${name}/zerotier/zerotier-ip/value")
+                      ]
+                    else
+                      ips
+                  ) [ ] machines;
+                  allHostIPs = networkIps;
+                in
+                {
+                  wantedBy = [ "multi-user.target" ];
+                  after = [ "zerotierone.service" ];
+                  path = [ config.clan.core.clanPkgs.zerotierone ];
+                  serviceConfig.ExecStart = pkgs.writeShellScript "zerotier-inventory-autoaccept" ''
+                    ${lib.concatMapStringsSep "\n" (host: ''
+                      ${config.clan.core.clanPkgs.zerotier-members}/bin/zerotier-members allow --member-ip ${host}
+                    '') allHostIPs}
+                  '';
+                };
+
+              clan.core.networking.zerotier.controller.enable = lib.mkDefault true;
+            };
+
+          };
+      };
+  };
+}

clanServices/zerotier/flake-module.nix

@@ -0,0 +1,9 @@
+{
+  lib,
+  ...
+}:
+{
+  clan.modules = {
+    zerotier = lib.modules.importApply ./default.nix { };
+  };
+}

clanServices/zerotier/shared.nix

@@ -0,0 +1,72 @@
+{
+  lib,
+  config,
+  pkgs,
+  roles,
+  instanceName,
+  ...
+}:
+let
+  controllerMachine = builtins.head (lib.attrNames roles.controller.machines or { });
+  networkIdPath = "${config.clan.core.settings.directory}/vars/per-machine/${controllerMachine}/zerotier/zerotier-network-id/value";
+  networkId =
+    if builtins.pathExists networkIdPath then
+      builtins.readFile networkIdPath
+    else
+      builtins.throw ''
+        No zerotier network id found for ${controllerMachine}.
+        Please run `clan vars generate ${controllerMachine}` first.
+      '';
+  moons = lib.attrNames (roles.moon.machines or { });
+  moonIps = builtins.foldl' (
+    ips: name:
+    if
+      builtins.pathExists "${config.clan.core.settings.directory}/vars/per-machine/${name}/zerotier/zerotier-ip/value"
+    then
+      ips
+      ++ [
+        (builtins.readFile "${config.clan.core.settings.directory}/vars/per-machine/${name}/zerotier/zerotier-ip/value")
+      ]
+    else
+      ips
+  ) [ ] moons;
+in
+{
+  config = {
+    clan.core.networking.zerotier.networkId = networkId;
+    clan.core.networking.zerotier.name = instanceName;
+
+    systemd.services.zerotierone.serviceConfig.ExecStartPost = lib.mkIf (moonIps != [ ]) (
+      lib.mkAfter [
+        "+${pkgs.writeScript "orbit-moons-by-ip" ''
+          #!${pkgs.python3.interpreter}
+          import json
+          import ipaddress
+          import subprocess
+
+          def compute_member_id(ipv6_addr: str) -> str:
+              addr = ipaddress.IPv6Address(ipv6_addr)
+              addr_bytes = bytearray(addr.packed)
+
+              # Extract the bytes corresponding to the member_id (node_id)
+              node_id_bytes = addr_bytes[10:16]
+              node_id = int.from_bytes(node_id_bytes, byteorder="big")
+
+              member_id = format(node_id, "x").zfill(10)[-10:]
+
+              return member_id
+          def main() -> None:
+              ips = json.loads(${builtins.toJSON (builtins.toJSON moonIps)})
+              for ip in ips:
+                  member_id = compute_member_id(ip)
+                  res = subprocess.run(["zerotier-cli", "orbit", member_id, member_id])
+                  if res.returncode != 0:
+                      print(f"Failed to add {member_id} to orbit")
+          if __name__ == "__main__":
+              main()
+        ''}"
+      ]
+    );
+
+  };
+}

docs/mkdocs.yml

@@ -86,6 +86,7 @@ nav:
           - reference/clanServices/borgbackup.md
           - reference/clanServices/hello-world.md
           - reference/clanServices/wifi.md
+          - reference/clanServices/zerotier.md
       - Clan Modules:
           - Overview: reference/clanModules/index.md
           - reference/clanModules/frontmatter/index.md